Massive β1-adrenergic receptor reaction explains irreversible Acute arrhythmia in a fatal case of acute pure caffeine intoxication

Caffeine, a naturally occurring purine-based alkaloid, is the most consumed psychostimulant worldwide. Since caffeine pharmacokinetics shows extreme interindividual variability, it is not easy to establish its toxic dose. Only a few cases of death due to acute caffeine intoxication have been described so far, the majority of which attributable to massive assumption of caffeine-based medications. We present a case of acute caffeine overdose due to ingestion of pure caffeine. The extremely high blood concentration of caffeine determined a strong cardiovascular response, leading to fatal arrhythmia, as supported by histological evidence of myocardial injury. Quantitation of catecholamines and their metabolites in urine samples was performed and showed level near the highest limit of normal ranges for norepinephrine and high level of epinephrine. Contraction band is a pathological modification of the myocell caused by the catecholaminergic action and can occur in conditions of alteration due to the interaction between calcium and catecholamines. We demonstrated the β1-adrenoceptor involvement in our fatal case by immunohistochemical analysis.